1. Field of the Invention
The present invention relates to a new azomethine, a process for the preparation thereof and also its use.
2. Discussion of the Background
Azomethines, better known under the name Schiff bases, are generally prepared by condensation of a primary amine and a carbonyl compound: ##STR4##
If the H.sub.2 O is removed from the equilibrium, the azomethine can be obtained in almost quantitative yield. However, primary 2-hydroxyamines react with carbonyl compounds to give a mixture of Schiff bases and oxazolidines (A. Paquin, B. 82, 316 (1949)), the two reaction products being in equilibrium with each other: ##STR5##
3- or 4-hydroxyamines react analogously with carbonyl compounds to give 6- or 7-membered ring systems.
Starting from a 4-hydroxyamine and a carbonyl compound, aldehyde or ketone, the Schiff base according to equation I can only be prepared as a mixture with a 7-membered N,O-heterocycle. A Schiff base from a 4-hydroxyamine would be of great interest for the preparation of poly(Schiff base)s, since hydrolysis would then give a simple route to polyamines which can be obtained only with great difficulty, if at all, in other ways.